Bacterial vaginosis ("BV") is a common, underdiagnosed condition afflicting millions of women in North America alone. Left untreated, BV can cause pelvic inflammatory disease, premature rupture of membrane, pre-term labour, and post-abortal and post-hysterectomy infections. Currently, diagnosis of BV occurs in two ways.
Firstly, the physician may diagnose BV by ordering a complete microbiological workup which involves the physician obtaining a sample of vaginal fluid, labeling the sample, packaging the sample and sending the specimen to a laboratory for analysis. This results in a two to four day turn around to receive the results from the laboratory. In addition, laboratory analysis of a vaginal smear is expensive.
Secondly, a diagnosis of BV may be made by the physician in his or her office when three or four criteria are met: 1) presence of clue cells; 2) an indicative vaginal discharge; 3) a pH of vaginal fluid greater than or equal to 4.5; and 4) a positive potassium hydroxide ("KOH") "whiff" test. (The four criteria are often referred to as the Amsel Criteria.)
The first criteria (criteria 1) is the presence of clue cells. To test for the presence of clue cells in the physician's office, the physician does a wet mount or gram stain where a swab of the vaginal fluid is taken and applied to a slide which the physician examines under the microscope. However, many physician do not routinely utilize microscopes in their office. If the physician does not wish to use a microscope, the physician must label, package and send the specimen to a laboratory, resulting in the above-referred to two or four day turn around in order to receive the results from the laboratory.
The second criteria (criteria 2) is the presence of an indicative vaginal discharge which is thin and homogeneous grey to white.
The third criteria (criteria 3) is a pH of the vaginal fluid which is equal to or greater than 4.5. Traditionally, the physician has had to manipulate pH paper to perform this test. This awkward and cumbersome.
The fourth criteria (criteria 4) is a positive KOH "whiff-test". Traditionally, the physician has performed this test by applying one to two drops of 10%-20% KOH solution to vaginal fluid which has been smeared on a slide. The physician then smells the sample. If the sample gives off a foul odour of dead fish, it is indicative of the presence of bacterially-derived amines including putrescine, cadverine, spermine and spermidine, which is therefore indicative of BV. The KOH whiff test has been, to date, cumbersome for the physician to perform.
Involving a laboratory in diagnosis can lead to delays in diagnosis of BV or the use of non-specific therapies being prescribed in the interim. To date, if the physician performs the diagnosis in his or her office, the need to manipulate various different apparatus as well as caustic substances such as KOH can possibly lead to delays in diagnosis or non-diagnosis of BV, also leading to non-specific therapies being prescribed or no therapy at all. Furthermore, there is a movement in the medical field, including by various societies of Obstetricians and Gynecologists, towards regular and routine screening of certain women for BV.
There is a need for a simple, self-contained, rapid and specific diagnostic test for BV that conforms to accepted diagnostic guidelines, can be performed in the physician's office and overcomes the problems mentioned above. If BV is ruled out, there is a need to determine the pH of vaginal fluid to assist in the diagnosis of other vaginal infections such as yeast infections.